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Biomedical subjects

D Benhamou

Publications and source records attributed to D Benhamou.

At least 145 records · Page 8Linked to original sources
PubMed1997

Increased intraperitoneal pressure up to 15 mm Hg does not reliably induce haemodynamic changes in pigs.

Haemodynamic alterations occur consistently with laparoscopic surgery in humans. These haemodynamic changes have never been reproduced in an animal model without additional potentiating factors. As these alterations may be deleterious in some patients and as the cause is only partly understood, we have used an animal model to study these changes. Pneumoperitoneum with intraperitoneal pressures of up to 15 mm Hg were produced in pigs, in the same way as for laparoscopic surgery in humans. Arterial pressure, cardiac output, pulmonary arterial pressure and systemic arterial resistance were assessed at baseline and after pneumoperitoneum had been produced. Intraperitoneal pressures of up to 15 mm Hg were not associated with consistent circulatory changes and we conclude that haemodynamic changes associated with laparoscopic surgery are dependent on species.

Animals↗
PubMed1997

Continuous extradural infusion of ropivacaine 2 mg ml-1 for pain relief during labour.

We have assessed the dose-response relationship of a solution of ropivacaine 2 mg ml-1, given as a continuous extradural infusion to women in labour. A total of 133 parturients were allocated randomly to one of four groups to receive a fixed rate ropivacaine infusion of 4, 6, 8 or 10 ml h-1 with additional bolus doses as necessary. Contraction pain, quality of analgesia, sensory block, motor block and neonatal Apgar scores were assessed. There were no significant differences between groups in terms of analgesia or motor block, although significantly more bolus doses were required by the group receiving 4 ml h-1 (P < 0.05 compared with the other groups), and a significantly higher total dose of ropivacaine was administered to the 10-ml h-1 group compared with the 6-ml h-1 group (P = 0.044). There were no significant differences between groups in terms of obstetric or neonatal outcome. We conclude that ropivacaine 2 mg ml-1 was effective and well tolerated when given as a continuous extradural infusion at 6-8 ml h-1 and may be used as the sole analgesic during labour.

Amides↗
PubMed1997

Aprotinin reduces blood loss in patients undergoing elective liver resection.

Ninety-seven patients undergoing elective liver resection through a subcostal incision were assigned to large-dose aprotinin treatment or placebo in a double-blind, prospective, randomized fashion. Randomization was stratified by diagnosis: (a) cancer in cirrhosis, (b) cancer in healthy liver, and (c) benign tumor in healthy liver. Intraoperative blood loss, percentage of transfused patients, and total transfusion requirement per group were significantly lower in the aprotinin group than in the placebo group (1217 +/- 966 mL vs 1653 +/- 1221 mL, P = 0.048; 17% vs 39%, P = 0.02; 30 vs 77 red blood cell packs, P = 0.015, respectively). Assessment of hematological markers (a) prior to surgery, (b) at the end of surgery, and (c) 24 h after surgery showed an identical intraoperative increase in thrombin-antithrombin III complexes in patients of both groups (P = 0.86), which indicates a similar activation of coagulation. Intraoperative hyperfibrinolysis was significantly less pronounced in the aprotinin group than in the placebo group (P = 0.0002 and P = 0.004 for D-dimers and fibrinogen, respectively). No adverse drug effects were detected (circulatory disturbances, deep venous thrombosis, increase in serum creatinine). These results suggest that aprotinin significantly reduces blood loss and transfusion requirement in patients undergoing elective liver resection through a subcostal incision.

Adult↗
PubMed1997

Comparison between conventional axillary block and a new approach at the midhumeral level.

We undertook this prospective, randomized study to compare the success rate, time spent performing the blocks, onset time of surgical anesthesia, presence of complete motor blockade, and lidocaine plasma concentrations between conventional axillary block and a new approach at the midhumeral level. Both techniques were performed using a peripheral nerve stimulator. Two nerves were located at the axillary crease, whereas four nerves were located at the midhumeral level. Sixty patients undergoing upper limb surgery were assigned to one of the two techniques. The sensory block was evaluated before surgery for all of the distributions of the four major nerves of the upper extremity. A subset of patients had lidocaine plasma concentrations determined. Times to perform the blocks, mean maximum plasma lidocaine concentration, and time to peak concentration were not different between groups. The success rate of the block, as well as the incidence of complete motor blockade, was greater with the midhumeral approach compared with the axillary approach. However, the onset time to complete anesthesia of the upper extremity was shorter in the axillary approach. For brachial plexus anesthesia, we conclude that the midhumeral approach provided a greater success rate than the traditional axillary approach.

Adult↗
PubMed1997

Intravenous nitroglycerin to relieve intrapartum fetal distress related to uterine hyperactivity: a prospective observational study.

During a 1-yr period, we evaluated prospectively the use of nitroglycerin (NTG) to relieve severe intrapartum fetal distress related to uterine hyperactivity. Sixty to ninety micrograms of NTG were injected intravenously (i.v.) within 2-5 min after onset of severe fetal distress after oxygen administration, left lateral decubitus, and discontinuation of any ongoing oxytocin infusion (62%) had failed to resolve the fetal heart rate abnormality. A second dose (60 or 90 micrograms) was used 2-3 min later as required. NTG was completely effective in 22 cases (fetal distress resolution within 4-5 min with restoration of normal uterine activity) and partially but sufficiently effective in the remaining 2 cases (fetal distress resolution within 4-5 min with residual mild uterine hyperactivity). However, a second dose was required for nine parturients (38%). Six parturients (25%) developed hypotension 2 min after the first NTG injection, with a mean nadir of 93.2 mm Hg (minimum 85 mm Hg). Hypotension was always rapidly reversed with a small single dose of ephedrine (4.5-6 mg). In conclusion, we found small doses (60-180 micrograms) of IV NTG to be associated with resolution of severe fetal distress related to uterine hyperactivity along with negligible side effects.

Adult↗
PubMed1997

Neurotoxicological assessment after intracisternal injection of liposomal bupivacaine in rabbits.

UNLABELLED: Experiments were performed on rabbits randomly assigned to intracisternally receive 0.3 mL of plain bupivacaine 5 mg/mL, liposomal bupivacaine 5 mg/mL, bupivacaine-free liposomes, or isotonic phosphate-buffered saline. Mechanical ventilation was initiated or intravenous dopamine was infused when respiratory depression or hypotension occurred. Seven days after the injection, the whole spinal cord was removed and histopathologic characteristics were studied on transverse sections. All preparations were devoid of phosphatidylcholine hydrolysis or oxidation compounds. Solutions without bupivacaine produced transient irritative signs that required sedation in most rabbits. Despite the similar duration of respiratory depression in groups receiving liposomal or plain bupivacaine, liposomes produced significantly prolonged motor blockade (126 vs 70 min). Correction of hypotension after plain bupivacaine required a longer dopamine infusion and larger doses than after liposomal bupivacaine (28 vs 18 min and 74 vs 47 mg). Necrosis was observed in the cervical area of two rabbits (one in the liposomal bupivacaine group and another in the phosphate buffer group). No demyelinated areas were noted in spinal cord examinations. We conclude that liposomal bupivacaine leads to a less severe sympathetic block and to a prolonged motor block, whereas histologic changes are not significantly different among groups. IMPLICATIONS: Multilamellar liposomes containing bupivacaine administered intracisternally to rabbits produce spinal cord histopathologic changes not significantly different from those observed with plain bupivacaine. Sustained release of bupivacaine from liposomes is suggested by the prolonged motor blockade and the reduced severity of arterial hypotension. Use of these liposomes could prolong the local anesthetic effects of bupivacaine.

Anesthetics, Local↗
PubMed1997

Influence of acute renal failure on FPIA rapid serum assay of midazolam and its main metabolite.

We recently developed a simple and fast assay technique, providing the possibility of monitoring of midazolam (M) during sedation. We compared HPLC vs FPIA for the measurement of the sum M plus alpha 1-hydroxymidazolam (OM), its main and pharmacologically active metabolite, in the serum of sedated ICU patients; this activity referred to as M-like. We identified certain patients in whom M-like activity appeared abnormally high in comparison with HPLC assays. Their common denominators were: long-term sedation with M, and seriously impaired renal function. Further, the conjugates of OM (OMG) accumulated in patients with acute renal failure could contribute to the sedation. We compared the metabolic and analytic behavior of M, OM, and OMG in 2 groups of sedated patients either presenting with normal renal functions (group 1) or with a picture of acute renal failure (group 2). Blood samples were assayed by HPLC and by FPIA and analysis was performed before and after hydrolysis of OMG. Before hydrolysis there was a dramatic accumulation of OMG in the patients of group 2, HPLC vs FPIA results were not different within group 1, while in group 2 the FPIA response exceeded that of HPLC. After hydrolysis, measurement by HPLC was greatly increased in group 2, in each group (vs HPLC) and from one group to another, the FPIA signal (the M-like activity) showed a significant increase. It would be important to take OMG into account as a coprotagonist in sedation whenever circumstances predispose to its accumulation.

Acute Kidney Injury↗
PubMed1997

[Asymptomatic mediastinal parathyroid adenoma].

A 74-year-old woman was hospitalised for pleuro-pneumonia of the right base. The chest x-ray showed the presence of a right paratracheal opacity which persisted during the course of the infectious episode. A computed tomographic scan of the thorax showed a voluminous anterior mediastinal mass which compressed the trachea without invading it. Surgical excision enabled the ablation of a tumour which was haemorrhagic and the histological examination established a diagnosis of cystic parathyroid adenoma. At anytime did the patient present either clinical symptoms or biochemical signs suggesting primary hyperparathyroidism.

Adenoma↗
PubMed1996

Obstetric patients treated in intensive care units and maternal mortality. Regional Teams for the Survey.

OBJECTIVE: To ascertain the frequency of serious diseases in pregnant women. STUDY DESIGN: A population based survey was performed in France. The cases were all the women admitted for treatment in intensive care unit (ICU). The severity of the cases was measured with the simplified acute physiology score (SAPS) the lethality and the rate of still birth. RESULTS: 435 obstetric patients were included. The estimated frequency of severe diseases was 310 S.D.36 per 100,000 live births. The most frequent diagnose that motived admission in ICU was hypertensive diseases. The lethality rates differed greatly between specific disorders. The lethality rate was lower when scheduled maternity was located in a teaching hospital. CONCLUSION: Regarding these results it appears that the majority of obstetric patients with severe diseases are referred to suitable care, but a small proportion of women who had to change their type of care registered a significant higher lethality.

Female↗
PubMed1996

[Combined spinal and epidural analgesia for labor. Prolongation by addition of a minidose of clonidine to sufentanil. An initial study].

The effect of adding a minidose of clonidine to intrathecal sufentanil during the early first stage of a painful labour was evaluated in this preliminary open-label, non-randomised trial. Group 1 received sufentanil 5 micrograms + clonidine 30 micrograms intrathecally (n = 10) and group 2 only intrathecal sufentanil 5 micrograms (n = 11). The two groups were not statistically different regard-ing age, weight, height, primiparity (67 vs 50%), oxytocin use (37 vs 60%), initial cervical dilation (m +/- DS: 2.9 +/- 1.1 vs 2.9 +/- 1 cm) and VAS pain scores (70 +/- 14 vs 68 +/- 19 mm). In group 1, analgesia was markedly prolonged with a reduced variability in duration: 146 +/- 27 min vs 95 +/- 44 min, (P = 0.006). VAS pain scores were: 14 +/- 20 vs 19 +/- 13, 1 +/- 3 vs 9 +/- 12, 0 vs 5 +/- 7, 48 +/- 12 vs 65 +/- 15, five and fifteen minutes after intrathecal injection, during maximum efficacy, and at the time additional analgesia was required, in group 1 and group 2, respectively. Analgesia evaluated with the VAS pain scores was better in group 1 compared with group 2 (P = 0.02) and decreased somewhat slower. Side effects, such as hypotension, pruritus and sedation, were not statistically different between groups. Nausea and motor blockade did not occur. In conclusion, the addition of a minidose (30 micrograms) of clonidine to sufentanil 5 micrograms given intrathecally seems to potentiate markedly the analgesia obtained during the early first stage of labour.

Adult↗
PubMed1996

Clonidine and or adrenaline decrease lignocaine plasma peak concentration after epidural injection.

Clonidine is an alpha 2-adrenoceptor agonist increasingly used in combination with lignocaine for spinal or epidural anaesthesia because of a prolonged analgesic effect. Life adrenaline, it may decrease lignocaine peak concentration (Cmax), thus leading to decreased toxicity. However, the effects of clonidine on resorption of lignocaine into the systemic circulation from the epidural space remain to be established. We studied the pharmacokinetics of lignocaine after epidural injection of lignocaine with or without clonidine, adrenaline and both drugs. Total body clearance and apparent volume of distribution were similar in the four groups, but the maximum observed concentration (Cmax) was markedly increased in the plain solution group as compared with the other groups; (plain lignocaine: 7.15 +/- 2.04 micrograms ml-1, lignocaine + adrenaline: 3.11 +/- 136 micrograms ml-1, lignocaine + clonidine: 4.48 +/- 1.26 micrograms ml-1, lignocaine + adrenaline + clonidine: 4.06 +/- 1.42 micrograms ml-1 [mean +/- s.d.]). Our results show that, clonidine decreases lignocaine Cmax to the same extent as adrenaline.

Adolescent↗
PubMed1996

Maternal and fetal effects of adrenaline with bupivacaine (0.25%) for epidural analgesia during labour.

The use of adrenaline added to bupivacaine during epidural analgesia for labour is controversial. The effects of epidural analgesia with bupivacaine containing adrenaline on maternal blood pressure and heart rate, uterine activity, progress of labour, fetal heart rate and Apgar scores, were assessed using visual analogue pain scores, upper level of sensory block and motor blockade in 60 parturients who were allocated randomly to receive: 10 mL of bupivacaine 0.25% plain (group I) or with adrenaline 5 micrograms mL-1 (group II) or with adrenaline 1.66 micrograms mL-1 (group III). The first stage of labour was significantly longer in group II than in group I [414 +/- 49 vs. 296 +/- 24 min (+/- SD)]. There were no other significant differences. It is concluded that adrenaline at 5 micrograms mL-1 significantly prolongs the first stage of labour. Neither adrenaline 5 micrograms mL-1 nor 1.66 micrograms mL-1 has any beneficial effect.

Analgesia, Epidural↗